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National Space Society announces Orbital Space Settlement Design Project

Artist’s impression of the interior of a 500m diameter cylindrical spin-gravity space settlement, whose detailed engineering design is one possible output of the NSS Orbital Space Settlement Design Project. Credits: Bryan Versteeg / Spacehabs.com

In a presentation at this year’s International Space Development Conference, which took place in McLean, Virginia, June 4th through June 7th, National Space Society (NSS) COO/SVP Dale Skran announced the kickoff of an open-source Orbital Space Settlement Design (OSSD) Project. The initiative has been under active development for over a year within the NSS Space Settlement Advocacy Committee (SSAC) and the NSS Board of Scientific and Technical Advisors (BSTA). Full disclosure: Yours truly is a member of the SSAC. It was officially approved as an NSS Project last March. The content of this post is based on Skran’s presentation, supplemented with subsequent material presented to the SSAC, with permission.

The current OSSD project Study Group core team consists of Dale Skran, Frederick (Rick) Jenet, PhD, and Bryce Meyer, with all BSTA and SSAC members actively involved in review and discussion. Work is currently focused on establishing a foundational set of design inputs in the form of “Questions” (see below). A dedicated workshop to refine these questions will be held at the NSS Space Settlement Summit taking place at the University of Central Florida, October 25th and 26th. This will be followed by a public announcement and formal request for comment from the broader community. In addition, the “OSSD Terms of Reference” (TOR) and the design input Questions will be located on a dedicated NSS website. The final recommendations will be published in the NSS Space Settlement Journal.

What are Terms of Reference?
The TOR is a formal document that defines the mandate, scope, responsibilities, boundaries, and working methods of the OSSD project. TORs are recursive — a large project such as this one can be subdivided, with each subdivision having its own TOR. This powerful technique is derived from the International Telecommunications Union (ITU) standards development process.

What is the Objective of the OSSD Project?

The core goal is to produce the first complete buildable engineering design for a rotating space settlement. The project is primarily an engineering and systems-design effort, not a policy activity, although legal and economic aspects are necessarily included because they affect feasibility.

Why Pursue This Project?

Rotating space settlements as envisioned by Gerard K. O’Neill will remain an empty dream until they become buildable realities. To many observers, it has not yet been fully established that such settlements are feasible. A fully realized engineering design will be a huge leap forward in making the case that settlements in free space lie in humanity’s future. The research and development required could also address many important issues back on Earth (e.g., closed-loop systems, resource efficiency, energy production, materials science, and robotics).

Why Should the NSS Lead This Effort?

The NSS is uniquely positioned because it is:

  • Non-partisan.
  • Not aligned with any particular company or region.
  • Interested in broadening access to space for all of humanity.
  • Possesses the necessary contacts to convene such a project.
  • Has the longevity and reputation to be taken seriously.
  • Can serve as a respected “honest broker” between different companies, products, technologies, and design approaches.
  • Operates as a non-profit.

Why Now?

Several converging factors make 2026 the right moment:

  • It is over 50 years since the landmark 1975 NASA-Ames space settlement summer study and since the founding of the L5 Society, which later merged with the National Space Institute in 1987 to form the NSS.
  • The NSS laid critical groundwork with the invitation-only Space Settlement 2021 Workshop (SSW), resulting in the book “A Dream Renewed: O’Neill’s Vision in the 21st Century,” a paperback/magazine provided to NSS members, ISDC attendees, and coming out in hardcover on August 25, 2026, available for pre-order.
  • Sufficient knowledge has accumulated, and technology has improved over five decades, such that O’Neill’s original concepts can be updated to a buildable design.
  • Low-cost, fully reusable launch vehicles — which existed only on paper in 1975 — are now a reality on the launch pad.
  • The open-source movement has demonstrated a path to the democratization of technology that was not envisioned in O’Neill’s era.
  • Increasingly powerful artificial intelligence tools now enable a relatively small science and engineering team to address large, complex design questions at a level impossible during O’Neill’s time.

Scope and Boundaries of the OSSD Project

Scope of the Engineering Design:

  • A place where people, including families, can safely live on a permanent, economically self-sustaining basis.
  • Nominal population target: 1,000, with analysis covering populations from 100 to 10,000 for comparison.
  • Designed for direct comparison to the 10,000-person NASA Ames summer study and the British Interplanetary Society (BIS) Avalon project.
  • Positioned as a component in a cislunar economic network (not required to be autarkic or totally biologically self-sufficient).
  • Assumes the baseline human species; human modification or enhancement is explicitly out of scope.
  • Design target: 1 gravity or a high fraction of 1g (since humans have evolved over millions of years on Earth, and the minimum gravity level for long-term human thriving in space has not been firmly established).

What’s included:

  • Engineering design for a rotating space settlement.
  • Examination and development of assumptions related to available construction materials and their costs.
  • Exploration of the legal, treaty, and economic prerequisites needed for the engineering design to be feasible.
  • Investigation of resilience to both natural and artificial assaults, with particular attention to electromagnetic hazards, biological threats, and meteor/space debris strikes.

What’s excluded (The idea being “Don’t boil the ocean”; i.e., focus only on the space settlement design, not all the other ancillary infrastructure and supply chains):

  • Lunar mass drivers
  • Lunar mining technology
  • Construction shacks
  • Asteroid mining technology
  • Launch vehicles
  • In-space transport vehicles
  • Detailed design of robotic construction equipment
  • Weapons systems for settlement defense that are not necessary to protect against natural phenomena
  • Military plans relating to settlement defense

What Happens Next? The Five-Year Roadmap

The project will proceed through disciplined, question-driven workshops rather than attempting to design everything at once:

  • NSS, led by the BSTA, will organize high level workshops to define specific design input questions, to be drafted at this fall’s Space Settlement Summit and subsequently flowed down to subordinate working groups.
  • The questions will be categorized into a few topic areas to help assign subject matter experts, such as High-level Requirements, Agriculture/Biological, and Physical/Construction.
  • The BSTA will assign Rapporteurs to lead these working groups in each question area.

NOTE: Each Rapporteur is expected to organize their work as they see fit and report at least annually to the BSTA with a readout of their progress, including draft recommendations. The normal working method will be workshops, but other means can be used. Unlike the ITU-T, which rotates its meetings across continents, workshops will typically be held in the USA, although this is not strictly required. Rapporteurs are unpaid volunteers, typically with jobs in the space industry

  • In a workshop, carefully framed draft questions will be presented and tagged with a dependency (i.e., TOR, Economic Model, Location, etc.) The questions form the intellectual backbone driving the entire OSSD project.
  • The workshop groups will do the hard work to define good questions with the core philosophy that “Good questions drive good answers.”
  • Workshops will cover a focused set of questions and continue until a Recommendation is produced to define a design output.
  • Target: After five years, the accumulated Recommendations will add up to a complete, buildable engineering design.

The Questions:

The following list is an evolving work in progress as of the date of this post, of potential questions to be finalized by the BSTA and then flowed down to the working groups to flesh out the details. It is by no means complete.

  1. What is the target reliability/safety standard? (Depends on TOR)
    Options range from aviation-like to nuclear-plant-like, to “ISS-like”. Telecom, chip, or automotive standards? This decision drives redundancy, inspection cadence, acceptable risk to children, and the critical safety-vs-uptime trade-off (space habitats cannot have downtime). It also requires choosing a reliability level target (e.g., 5-sigma vs. 6-sigma) and deciding which parts of the habitat are held to which standards.
  2. What are the core services provided to residents? (Depends on TOR – for discussion)
    Includes housing space per person, privacy, recreation, food variety, internet latency, and governance/rights baseline. The question invites comparison to services provided by a small town on Earth and asks how to avoid the tragedy of the commons for “free goods,” while also defining the proper limits of what planners/designers should dictate.
  3. What is the Economic Model? (Depends on Q4)
    This involves answering fundamental questions like: How will settlers add economic value? How will the settlement be economically sustainable?
  4. Where exactly in cislunar space will the settlement be located? (Depends on TOR)
    Candidate locations: Near-Rectilinear Halo Orbit (NRHO), distant retrograde orbit, Earth-Moon Lagrange (EML)1/EML2 halo, high lunar orbit, or EML4/EML5. Location dramatically affects eclipses, station-keeping, communications, debris environment, thermal design, and the economic model itself.
  5. What is the logistics doctrine with Earth? (Depends on Q3, Q4)
    Covers cadence for spares and consumables, allowed lead times, acceptable downtime, and precisely which items must be “topped off” and how often. Items such as trace elements, pharmaceuticals, replacement electronics, specialty foods, nitrogen/argon, etc. need to be defined. Spares/consumables strategy may itself be an outcome of the economic model rather than a question per se.
  6. What population size and target demographics are required for social stability? (No dependency)
    Includes sex ratio, age distribution, and other demographic factors. Questions about non-cisgender humans are out of scope. This is not to exclude them explicitly, but the intent of the question is to focus on critical biological issues.
  7. What population size is required for operational stability? (No dependency)
    Focuses on skill sets, trades, and degree of automation needed for settlers to maintain safe operations. May depend on downstream recommendations about agriculture and other operations.
  8. What population size is required for economic viability? (Depends on Economic Model)
    Considers export/service revenue versus internal labor needs, degree of specialization, downtime tolerance, training pipeline, and explicitly excludes a small population of the very rich as a viable model.
  9. What population size, including pets, is required for mental health? (No dependency)
    Studies have found that 1 in 20 people who overwinter in Antarctica develop serious mental health issues. This suggests that a population of ~200 (typical Antarctic winter-over size) may be too small, or that aspects of the Antarctic station model need correction for space application.
  10. Therefore, what is the minimum viable steady-state population? (Depends on the Q6, Q7, Q8, Q9)
    A synthesizing question that derives a minimum that satisfies the criteria from the related questions, with a suggested floor of 100 occupants.
  11. What governance model applies? (Depends on TOR)
    The TOR states that the settlement is assumed to be under the legal jurisdiction of the launching state. The question explores issues arising from applying the laws of the launching state to the settlement and how those issues can be resolved.
  12. What Ownership Model Applies? (Depends on Economic Model)
    This question is strongly linked to the economic purpose of the settlement, and should cover corporate ownership/company townships, co-ops, condominiums, employee-owned corporations, and other models.
  13. What international legal regime is required to allow the first settlement to be funded? (Depends on TOR)
    Focuses on what legal interpretation of the Outer Space Treaty is necessary to permit construction of a settlement in orbital space.
  14. What maximum rotation rate (rpm) is acceptable for a multi-generation population? (Depends on TOR)
    Because artificial gravity is fixed at approximately 1g, the rotation rate directly sets the required radius, which in turn drives structural mass and construction approach. Why 1g? The TOR states: “Since the minimum gravity level for human thriving has yet to be firmly established, the design target will be either 1 gravity or a high fraction of 1 gravity…” I’ve posted on the topic previously.
  15. What radius/geometry follows from the g level and rpm? (Depends on Radius, also TBD)
    Explores torus vs. cylinder vs. multi-ring vs. hammerhead configurations, habitable deck layout, and zoning.
  16. What is the docking/visiting vehicle strategy relative to rotation? (Depends on Q15)
    Will there be total spin-down? Will there be a non-rotating hub, and if so, how will the transfer from rotating-to-nonrotating spaces be accomplished?
  17. What radiation standard do we design to for families/children? (Depends on Q1)
    Annual dose targets, pregnancy limits, and Solar Particle Event shelter requirements need to be specified. Note that Medevac doesn’t help for chronic exposure to Galactic Cosmic Radiation.
  18. What shielding approach meets Q17 at minimum mass/cost? (Depends on Q17, Q4)
    Decisions on how bulk shielding (e.g. water and/or regolith) will be distributed, need to be made, accounting for storm shelters. Shielding-as-storage, active shields, and layered shields should be considered.
  19. Where does shielding mass come from? (Depends on Q4, Q18)
    Weigh the options of Earth-launched vs lunar-derived vs extracted from an asteroid, keeping in mind that sourcing material for initial habitats may change for future growth.
  20. What closure level is required to be “permanent” with imports allowed? (Depends on Q2, Q3, Q4, Q5)
    Define which consumables must be recycled (e.g., water, oxygen, nitrogen) vs what can be imported.
  21. What food system meets nutrition, variety, and psychological considerations at minimum mass/power? (Depends on Q10, Q20, Q25)
    The hydroponics/vertical farming mix, lighting strategy, protein plan, and storage buffers all need to be determined, fully considering the recycling system and ecological balance of the biosphere.
  22. What will be the atmosphere model and fire safety regime? (Depends on Q1, TOR)
    The total pressure, O₂ fraction, diluents (N₂/Ar), toxic pollutants control, and fire suppression doctrine all need to be determined.
  23. What water/waste architecture achieves Q20 with acceptable failure modes? (Depends on Q1, Q2, Q20)
    Water recovery, sanitation, pathogen control, waste processing, and a plan for “what if” contingencies need to be defined.
  24. How can an overly clean habitat environment be avoided? (TBD)
    Children who grow on farms have very low allergy rates; we want to make sure kids in the settlement are exposed to diseases to develop their immune systems.
  25. What total power level is required (steady state and peak)? (Depends on Q1, Q3, Q21, Q23)
    This will be a cumulative summing the contributions from the habitat, agriculture, industry, propulsion, and reserves.
  26. What power source architecture is optimal in cislunar space?(Depends on Q4, Q25)
    Solar vs nuclear vs hybrid, taking into account storage needs, safety considerations, and maintenance.
  27. What thermal rejection system is required? (Depends on Q25, TBD)
    This will drive radiator design, cooling system loops, heat reuse, zoning, and orientation constraints.
  28. What minimum local manufacturing/repair capability is required? (Depends on Q5, Q9)
    Operations to consider include, but are not limited to, planning for spare parts, maintenance of seals/filters, facilities for machining, electronics repair, additive manufacturing, and QA.
  29. What structural concept meets loading requirements, while taking into account micrometeoroids, internal pressure, and rotation rate, and minimizing mass? (Depends on Q4, Q15, Q18, Q22)
    At a minimum, requires consideration of materials, compartmentalization approach, Whipple shielding design, and pressure hull segmentation.
  30. What is the assembly and spin-up strategy? (Depends on Q4, Q15, Q18, Q29)
    Requires decisions on which modules are preassembled vs built on-orbit. Will the construction be carried out robotically or by crew? What is the optimal timing of when shielding is added, taking into account how balance will be maintained when rotation is initiated?
  31. What is the fault-tolerant operations concept? (Depends on Q1, Q10, Q28)
    This will help determine the staffing requirements, levels of training, emergency response procedures, maintenance cycles, inspection needs, spares policy, and cross-training.
  32. What are the top “design basis accidents” and how are they handled? (Depends on Q1, Q22, Q23, Q29, Q31)
    Scenarios include, but are not limited to, fire, depressurization, toxic release, collision, loss of rotation control, and loss of power.
  33. What is the growth path from the minimum viable system to a larger one? (Depends on Q15, Q18, Q29, Q30)
    This question will help to decide when to add rings/modules, how governance and economy scale, and how to avoid redesign.

O’Neill’s Vision of Free Space Settlements is Closer Than Ever

The OSSD project is a major strategic step for the NSS. After completing and publishing the foundational 2021 workshop proceedings in both accessible paperback and soon-to-be-released premium hardback formats, the organization is now moving from vision and discussion to disciplined, engineering-driven action. By framing the project around a rigorous, design input question methodology with clear scope boundaries, plans to assign rapporteurs, workshop processes, and a five-year horizon for producing buildable recommendations, the NSS is taking the lead as the honest broker and convening authority capable of coordinating the complex, multi-disciplinary work required to turn O’Neill’s dream of rotating space settlements into engineering reality.

The interactive workshop approach using carefully crafted design questions demonstrates a commitment to grassroots community input and iterative refinement rather than a top-down prescription. The careful separation of in-scope engineering/systems issues from excluded topics (launch vehicles, mining technology, mass drivers, etc.) shows a mature project management philosophy designed to keep the effort focused and achievable.

In summary, the OSSD Project will bridge the inspirational legacy of Gerard K. O’Neill and the 1975 NASA-Ames study with the practical realities of 2026: reduced launch costs via reusable rockets, open-source methodology, powerful leverage of AI, accumulated knowledge, and an organized NSS ready to lead the next phase of space settlement engineering. This initiative is positioned as the logical next step after the SSW book — turning the “long list of areas for future research” identified in that publication into concrete, actionable engineering questions whose answers will collectively constitute the first credible, buildable design for a rotating space settlement. Visit the NSS OSSD project website for updates. Let’s make it happen!

Artist’s rendering of what the interior of a 125m diameter rotating space settlement might look like; another possible outcome from the NSS OSSD project. Credits: Bryan Versteeg / Spacehabs.com
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Homing in on the Gravity Prescription

Image of the JAXA Kibo module on the International Space Station which houses the MARS short arm centrifuge for artificial gravity studies. Credit: NASA/JAXA

The Gravity Prescription (GRx), a term first coined by Dr. Jim Logan, refers to the minimum “dosing” of gravity (level and duration of exposure) to enable healthy conception, gestation, birth and normal, viable development to and throughout adulthood as a human being…over multiple generations. It should be noted that the GRx can be broken down into at least three components: the levels needed for healthy pregnancy (conception through birth), early child development, and adulthood.

The Japan Aerospace Exploration Agency (JAXA) has been studying the adult gravity prescription for mitigation of mammalian physiological issues that arise in space due to microgravity using mice for about a decade. To conduct this research, they’ve been using the Multiple Artificial-gravity Research System (MARS) short arm centrifuge in the Kibo module on the International Space Station (ISS). This will help us understand what dosing level of gravity is required to prevent the myriad of health issues (e.g., serious reduction in bone and muscle mass, ocular changes, weakening of the immune system – there are many more) that arise in mature adults when exposed for long periods to microgravity, to inform countermeasures for long-duration spaceflight and settlement.

By way of background, I reported back in 2021 on JAXA’s first long-term mouse study comparing mice reared under microgravity conditions to a cohort raised under 1g artificial gravity in the MARS centrifuge, which found that Earth-normal artificial gravity appears to prevent the negative health effects of microgravity. In the same post, I provided an update upon publication of the results of a second experiment executed a couple of years later, which tested mice in Moon gravity and found that 1/6g prevents muscle atrophy in mice, with the downside that this level of artificial gravity cannot prevent changes in muscle fiber (myofiber) and gene modification induced by microgravity. There appeared to be a threshold between 1/6g and Earth-normal gravity, yet to be determined, for skeletal muscle adaptation. Then in 2023 we got a few more data points helping us zero in on the right dose, at least for the adult GRx, between Moon and Earth levels of gravity.

I mentioned this new preliminary data in my presentation at ISDC 2024 on how the GRx may impact the future of space settlement. The results came from a NASA-funded experiment in cooperation with JAXA, headed by Dr. Mary Bouxsein and collaborators, that studied adult mice launched to the ISS on SpaceX CRS-27. The mice were split into four groups and dosed in the MARS centrifuge at four levels of gravity (microgravity, 0.33g, 0.67g, and 1g). The results were presented at the American Society for Gravitational and Space Research (November 2023). Still, no formal paper had been published at that time, only an abstract from the conference talk. Preliminary results showed that hindquarter muscle strength increased commensurate with the level of artificial gravity, indicating that spaceflight-induced atrophy can be mitigated with artificial gravity – more is better. Now the full study has finally been published in Scientific Advances with further details.

After each of the cohorts were individually treated to the four gravity levels in the MARS centrifuge and returned to Earth, the mice were euthanized and the researchers examined their soleus muscle (the calf muscle which is very sensitive to gravity levels), along with strength tests and blood biomarkers.

Key findings included:

  • Muscle shrinkage (atrophy): In microgravity, the soleus muscle fibers shrank noticeably. At 0.33g, the muscle cross-sectional area was largely preserved—meaning it didn’t lose much mass. Higher gravity (0.67g and 1g) also protected muscle size.
  • Muscle fiber type: Muscles have different fiber types—slow-twitch (good for endurance) and fast-twitch. Microgravity causes slow fibers to switch to fast ones. 0.33g partially prevented this switch, but 0.67g fully stopped it, keeping the muscle composition closer to normal.
  • Muscle function: Strength tests (like grip strength) and electrical measurements showed that 0.67g was enough to maintain overall muscle performance. Lower gravity levels did not fully protect function.

The study also found 11 blood metabolites (small molecules that are intermediate or end products of metabolism) that changed depending on gravity level. These could serve as future biomarkers to monitor astronauts’ health without invasive tests.

Why does this matter? This is the first experiment to identify the adult GRx thresholds for muscle health. It suggests that 0.33g (close to Mars-level) helps prevent muscle weakening, but titrating to 0.67g is needed to fully maintain strength and normal muscle condition. For future space stations or vehicles with rotating sections to create artificial gravity, this information is valuable: partial gravity helps, but at least 0.67g is better for long-term missions. Crucially, these results could inform the spin-rate specifications for a Mars Cycler to generate artificial gravity to maintain muscular function for travelers to and from Mars.

In short, the paper shows that even moderate artificial gravity could mitigate the musculoskeletal problems astronauts face in space, helping keep crews healthier on deep-space journeys. The research used careful controls, multiple measurement methods, and advanced analysis to reach these clear conclusions.

The bigger question is what is the GRx for reproduction? If permanent settlements are to be established in space, they should be (in the long run) at destinations that enable biological self-sustainability, meaning we will want to have healthy children and raise families there as we expand out into the solar system.

One study conducted by Japanese researchers in 2019 aboard the ISS suggested that mouse embryonic growth may be possible in microgravity. But this experiment was only 4 days of embryo development, which took place after conception. Another study of pregnant mice from the shuttle era found serious issues with brain development after exposure to microgravity. These are just snapshots of embryo and later fetus development, and only in microgravity. There still have not been rigorous scientific experiments covering the full mammalian reproductive cycle through all its phases under variable gravity conditions mimicking the Moon, Mars, or higher levels below that of our home planet.

Conceptual AI generated image of an expectant mother in Earth orbit under appropriate GRx dosing conditions after mammalian reproduction has been validated via higher animal models through all stages of pregnancy for a safe level of artificial gravity. An appropriate level of radiation shielding would also be required and is not shown in this illustration. Credit: MS Designer

It is vitally important as the private space stations begin to replace the ISS and space tourism takes off (including maybe even hotels on the Moon), that we understand the risks and implications for having babies off Earth in lower gravity environments. Alex Layendecker, the founder of the nonprofit Advanced SpaceLife Research Institute (ASRI), told me the following in an interview about his Green Paper on Sex in Space: Consideration of uncontrolled human conception in emerging space tourism:

“With mass access to space, we’ll soon have groups of individuals going up solely for vacation/leisure purposes, and you can be assured some of them will be engaging in sexual activity.  While it would be absurd to try to implement or enforce laws preventing sexual activity in those environments, the dangers associated with potential conception still exist.  What is critically needed at this point is a better collective understanding of those dangers, their mitigation, and for space companies to be able to provide those paying customers with enough information that informed consent can be established – space is inherently dangerous already, and people launching into space are briefed on that.”

Besides JAXA and some limited research by NASA, there are just a couple of organizations dedicated to studying the GRx for reproduction. ASRI based at Cape Canaveral and a Dutch company called SpaceBorn United. SpaceBorn has space missions planned in the next few years using their ARTIS (Assisted Reproductive Technology in Space) platform, focused on mammalian conception and early embryo development, with a prototype “space-embryo-incubator” capable of treating samples with adjustable artificial gravity. Initial missions will send this device to space with male and female mouse gametes, where in vitro conception and 5-6 day embryo development will proceed under artificial gravity conditions. The embryos will then be cryogenically frozen and returned to Earth where, if approved, they will be implanted in natural wombs, where the pregnancy will progress on Earth. If successful, subsequent phases over the next couple of decades will focus on increasing stages of pregnancy in space and early embryo development on the Moon.

But SpaceBorn’s platform is a small, automated self-contained centrifugal device operated in microgravity. To really study the GRx for mammalian reproduction, a fully equipped (preferably crewed) variable gravity biolab large enough to rear lower organisms from conception through pregnancy to birth, maturing into adulthood – over multiple generations and progressing successively in higher mammals – would be required. A very tall order! But there are reasonable and well-thought-out concepts for such facilities I’ve explored here previously.

Currently, there are only a couple of companies with rotating space stations in their strategic plans to provide larger-scale artificial gravity laboratories that could be used for reproductive studies. Vast Inc., a well funded, privately held startup, explicitly lists an Artificial Gravity Station targeted for around 2035 in its official product roadmap, a long cylindrical design that will rotate end-over-end at ~3.5 RPM to create artificial gravity for long-term habitation. It would build on their modular (non-rotating) Haven-1 module currently planned for launch in 2027 and the follow-on Haven-2 station which would gradually add units, eventually leading to a 9-module configuration slated for 2032.

Conceptual illustration of Vast Space Haven-2 nine module configuration space station that could be placed in Earth orbit as soon as 2032. Credit: Vast Space

Above Space, with aspirations for rotating wheel type space stations in the 2030s, has significant engineering and funding hurdles, but is the only other player that has plans for variable gravity facilities in space.

In my presentation at ISDC2024 linked earlier in this post, I advocated for determining the GRx for reproduction sooner rather than later, especially given Elon Musk’s timelines for colonizing Mars. As Musk has made clear for years and with his recently revealed SpaceX compensation package tied to it, his vision for the company is to make humanity multiplanetary and build a city on Mars with a million people. Up until recently, he was projecting mid-century to achieve that milestone. His shifting focus from Mars to the Moon aside, does he expect the population of his Martian colony to be composed of just adults? Musk, who has warned of population collapse and low fertility rates here on Earth as one of humanity’s biggest challenges, has been quoted as saying, “People are going to have to revive the idea of having children as a kind of social duty. If you can, and are so inclined, you should. Otherwise civilization will just die.”

Image of Elon Musk holding his son X AE X-II after Grimes gave birth to him in May 2020. Credit: Elon Musk

I’m pretty sure he envisions that the people occupying his city on Mars will want to have children there. And he’d probably want to know the GRx for reproduction well before significant numbers of people began migrating there to stay. A variable gravity research facility in low Earth orbit dedicated to studying mammalian physiology, including reproduction in less than 1g, could be built using SpaceX hardware and would not cost much more than Musk’s pocket change, but I’ve seen no indication that this is a priority for him.

Of course, there are others, affectionately called O’Neillians, who say we know 1g works, so let’s not waste time and just get started building rotating space settlements like Kalpana One, a 500m diameter starter unit located in equatorial low Earth orbit. Shielded by Earth’s magnetic field and therefore requiring less mass for radiation shielding, it would be much easier to accomplish than the enormous miles-long settlements O’Neill envisioned to be placed out at Earth-Moon Lagrange Point L5. The attractiveness of this approach (in LEO) may be waning with the rise of AI and what will likely be a proliferation of orbital data centers in the next few years. Cowboy Space has just filed with the FCC for a literal Stampede of 20,000 satellites adding to the queue of companies seeking regulatory approval for their megaconstellations, including Blue Origin’s Project Sunrise (51,600), Starcloud (88,000), and SpaceX’s 1 million satellites, all in sun-synchronous orbits ranging from 500 to 2000 kilometers. It may be getting pretty crowded up there soon, increasing the risk of collision with large cross-section space stations that are not easily maneuvered out of the way.

Personally, my view has evolved on the urgency for determining the GRx for reproduction on the Moon or Mars. I still hold that healthy human reproduction in lower-gravity environments is highly uncertain, given millions of years of evolution in Earth’s gravity, and carries a substantial risk of complications at every stage of reproduction. Being inspired by O’Neill, I was admittedly biased toward his approach to mitigate these risks and had a preference for spacious artificial gravity worlds. This led me to believe that if we confirmed through studies of the GRx for reproduction that having children in less than 1g could lead to dangerous complications and, therefore, be morally wrong, the information might bend the arc of space development toward free space settlements. Knowing we could not have children on the Moon or Mars might start to change the mindset of many space settlement advocates, whom the great science fiction author Isaac Asimov called planetary chauvinists, leading to diversion of resources toward building the infrastructure needed to construct rotating space settlements like Kalpana. I’m old enough to remember that O’Neill invented one of the key technologies for building these huge structures: a mass driver intended to be placed on the Moon to launch massive amounts of lunar regolith into space so that it could be processed into radiation shielding for these colonies. Advances in robotics, in situ resource utilization (ISRU), in-space assembly, life support systems, and many other technologies are needed to enable O’Neill colonies. Many of them are proceeding at pace anyway, but I thought that if we found the GRx for reproduction was not less than 1g, it would put a sense of urgency around these efforts.

However, it looks like market forces may be changing all this. I did not anticipate Elon Musk advocating for mass drivers on the Moon. Though he says they would be used for launching SpaceX’s AI satellites, the infrastructure for ISRU and electromagnetic launchers looks like it may be coming to Luna sooner than we expected and can certainly be retooled to fling regolith into space for shielding rotating space settlements, even larger ones, if the drive (and markets) are there.

But rather than the GRx for reproduction being the determining factor for where we settle space – planetary surfaces or free space colonies – a split life cycle may be the solution. This approach, credited to Kelly and Matt Weinersmith in their book A City on Mars, suggests using both destinations! As clarified in a presentation at ISDC2024 by Dale Skran, Chief Operating Officer & Senior Vice President of the National Space Society, this new way of thinking (not an official position of NSS) acknowledges that we probably need Earth normal gravity for having children and suggests that a rotating space station birthing center be placed in orbit above surface colonies on the Moon or Mars. Couples would conceive, bear children, and raise them in a healthy artificial gravity crèche, allowing them to mature to early adulthood, after which families or individuals may choose to remain in space or relocate to the low-gravity surface communities below.

So research by Dr. Bouxsein et al. may be homing in on the adult GRx, with the results from their study paving the way for practical countermeasures against health issues adult astronauts will face in microgravity on long-duration missions in space. But the artificial gravity dose level for reproduction needs much further study before we can safely say biologically self-sustaining space settlements in less than 1g will be possible. Until then (and after, if the answer is no), split life cycle communities may be the strategy for an expanding population migrating out into the solar system and beyond.

Artist’s impression of the interior of Kalpana One, a cylindrical rotating colony providing Earth normal artificial gravity for healthy living in space. With the coming proliferation of AI orbital data centers later this decade, this approach may lose favor in LEO, but could be one possible in-space component of a split life cycle solution for settlement of the Moon or Mars. Credits: Bryan Versteeg / spacehabs.com

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The impact of the Gravity Prescription on the future of space settlement

Artist rendering of a family living in a rotating free-space settlement based on the Kalpana Two design, with a length of 110m and diameter of 125m. Credits: Bryan Versteeg / Spacehabs.com

This post summarizes my upcoming talk for the Living in Space Track at ISDC 2024 taking place in Los Angeles May 23 – 26. The presentation is a distillation of several posts on the Gravity Prescription about which I’ve written over the years.

Lets start with a couple of basic definitions. First, what exactly is a space settlement? The National Space Society defined the term with much detail in an explainer by Dale L. Skran back in 2019. I’ve extracted this excerpt with bolded emphasis added:

Space Settlement is defined as: ​

​“… a habitation in space or on a celestial body where families live on a permanent basis, and that engages in commercial activity which enables the settlement to grow over time, with the goal of becoming economically and biologically self-sustaining …”

​The point here is that people will want to have children wherever their families put down roots in space communities. Yes, a “settlement” could be permanent and perhaps inhabited by adults that live out the rest of there lives there, such as in a retirement community. But these are not biologically self-sustaining in the sense that settlers have offspring that are conceived, born and raised there living out healthy lives over multiple generations.

Next we should explain what is meant by the Gravity Prescription (GRx). First coined by Dr. Jim Logan, the term refers to the minimum “dosing” of gravity (level and duration of exposure) to enable healthy conception, gestation, birth and normal, viable development to adulthood as a human being…over multiple generations. It should be noted that the GRx can be broken down into at least three components: the levels needed for pregnancy (conception through birth), early child development, and adulthood. The focus of this discussion is primarily on the GRx for reproduction.

We should also posit some basic assumptions. First, with the exception of the GRx, all challenges expected for establishment of deep space settlements can be solved with engineering solutions (e.g. radiation protection, life support, power generation, etc…)​. The one factor that cannot be easily changed impacting human physiology after millions of year of evolution on Earth is gravity. We may find it difficult or even impossible to stay “healthy enough” under hypogravity conditions on the Moon or Mars, assuming all other human factors are dealt with in habitat design.

Lets dive into what we know and don’t know about the GRx. Several decades of human spaceflight have produced an abundance of data on the deleterious effects of microgravity on human physiology, not the least of which are serious reduction in bone and muscle mass, ocular changes, and weakening of the immune system – there are many more. So we know microgravity is not good for human health after long stays. Clearly, having babies under these conditions would not be ethical or conducive for long term settlement.

The first studies carried out on mammalian reproduction in microgravity took place in the early 1990s aboard the Space Shuttle in a couple of experiments on STS-66 and STS-70. 10 pregnant rats were launched at midpregnancy (9 days and 11 days, respectively) on each flight and landed close to the (22 day) term. The rat pups were born 2 days after landing and histology of their brain tissue found spaceflight induced abnormalities in brain development in 70% of the offspring.

It was not until 2017 that the first mammalian study of rodents with artificial gravity was performed on the ISS. Although not focused on reproduction, the Japan Aerospace Exploration Agency (JAXA) performed a mouse experiment in their Multiple Artificial-gravity Research System (MARS) centrifuge comparing the impact of microgravity to 1g of spin gravity. ​The results provided the first experimental evidence that mice exposed to 1g of artificial gravity maintained the same bone density and muscle weight as mice in a ground control group while those in microgravity had significant reductions.

Diagram depicting an overview of the first JAXA Mouse Project in the MARS centrifuge with photos of the experiment on the ISS. Credits: Dai Shiba et al. / Nature. http://creativecommons.org/licenses/by/4.0/

In 2019 JAXA carried out a similar study in the MARS centrifuge adding lunar gravity levels to the mix. This study found that there were some benefits to the mice exposed to 1/6g in that Moon gravity helped mitigate muscle atrophy, but it did not prevent changes in muscle fiber or gene expression​.

Just last year, a team led by Dr. Mary Bouxsein at Harvard Medical School conducted another adult mouse study on the MARS centrifuge comparing microgravity, .33g, .67g and 1g. They found that hind quarter muscle strength increased commensurate with the level artificial gravity concluding, not surprisingly, that spaceflight induced atrophy can be mitigated with centrifucation. The results were reported at the American Society for Gravitational and Space Research last November.​

Returning to mammalian reproduction in space, an interesting result was reported last year in the journal Cell from an experiment by Japanese scientists at the University of Yamanashi carried out on the ISS in 2019. The team, headed up by Teruhiko Wakayama, devised a way to freeze mouse embryos post conception and launch them into space where they were thawed by astronauts and allowed to develop in microgravity. Control samples were cultured in 1g artificial gravity on the ISS and Earth normal gravity on the ground. The mouse embryos developed into blastocysts and showed evidence of cell differentiation/gene expression in microgravity after 4 days​. The researchers claimed that the results indicated that “Mammals can thrive in space”. This conclusion really can’t be substantiated without further research.

Which brings us to several unknowns about reproduction in space. SSP has explored this topic in depth through an interview with Alex Layendecker, Director of the Advanced SpaceLife Research Institute. Yet to be studied in depth is (a) conception, including proper transport of a zygote through the fallopian tube to implantation in the uterus. Less gravity may increase the likelihood of ectopic pregnancy which is fatal for the fetus and could endanger the life of the mother; (b) full gestation through all stages of embryo development to birth​; and (c) early child development and maturation to adulthood in hypogravity​. All these stages of mammalian reproduction need to be validated through ethical clinical studies on rodents progressing to higher primate animal models before humans can know if having children in lower gravity conditions on the Moon or Mars will be healthy and sustainable over multiple generations.

AI generated image of an expectant mother with her developing fetus in Earth orbit after mammalian reproduction has been validated via higher animal models through all stages of pregnancy for a safe level of gravity. An appropriate level of radiation shielding would also be required and is not shown in this illustration. Credit: DALL-E-3

Some space advocates for communities on the Moon or Mars have downplayed the importance of determining the GRx for reproduction with the logic that a fetus in a woman’s uterus on Earth is in neutral buoyancy and thus is essentially weightless. Therefore, why does gravity matter? ​ I discussed this question with Dr. Layendecker and he had the following observations paraphrased here: True, gravity may have less of an impact in the first trimester. But on the cellular level, cytoskeletal development and proper formation/organization of cells may be impacted from conception to birth​. Gravity helps orient the baby for delivery in the last trimester​ and keeps the mother’s uterine muscles strong for contractions/movement of the baby through the birth canal​. There are many unknowns on what level of gravity is sufficient for normal development from conception to adulthood.

Why does all this matter? Ethically determining the right level of gravity for healthy reproduction and child development will inform where families can safely settle space​. The available surface gravities of bodies where we can establish communities in space cluster near Earth, Mars and Moon levels​. These are our only GRx options ​on solar system bodies.

Gravity level clustering of solar system bodies available for space settlement. Credit: Joe Carroll

The problem is that we don’t yet know whether we can remain healthy enough on bodies with gravity equivalent to that on the Moon or Mars, so we can’t select realistic human destinations or formulate detailed plans until we acquire this knowledge​. Of course we can always build rotating settlements in free space with artificial gravity equivalent to that on Earth. Understanding the importance of the GRx and determining its value could change the strategy of space development in terms of both engineering and policy decisions. The longer we delay, the higher the opportunity costs in terms of lost time from failure to act​.

What are these opportunity cost lost opportunities​? Clearly, at the top of Elon Musk’s list is “Plan B” for humanity, i.e. a second home in case of cataclysmic disaster such as climate change, nuclear war, etc. This drives his sense of urgency. From Gerard K. O’Neill’s vision in The High Frontier, virtually unlimited resources in space could end hunger and poverty, provide high quality living space for rapidly growing populations​, achieve population control without war, famine, or dictatorships​. And finally, increase freedom and the range of options for all people​.

If humans can’t have babies in less than Earth’s gravity then the Moon and Mars may be a bust for long term (biologically sustainable) space settlement.​ There will be no biologically sustainable cities with millions of people on other worlds unless they can raise families there​.

Spin gravity rotating space settlements providing 1g artificial gravity may be the only alternative​. If Elon Musk knew that the people he wants to send to Mars can’t have children there, would he change his plans for a self-sustaining colony on that planet?​ Having and raising children is obviously important to him. As Walter Isaacson wrote in his recent biography of Musk, “He feared that declining birthrates were a threat to the long-term survival of human consciousness.”

So how could he determine the GRx quickly? One solution would be to fund a partial gravity facility in low Earth orbit to run ethical experiments on mammalian reproduction in hypogravity. Joe Carroll has been refining a proposal for such a facility, a dual dumbbell Moon/Mars low gravity laboratory which SSP has covered, that could also be marketed as a tourist destination. Spinning at 1.5 rpm, the station would be constructed from a combination of Starship payload-sized habitats tethered by airbeams allowing shirt sleeve access to different gravity levels​. Visitors would be ferried to the facility in Dragon capsules and could experience 3 gravity levels with various tourist attractions​. The concept would be faster, cheaper, safer and better than establishing equivalent bases on the Moon or Mars to quickly learn about the GRx​. The facility would be tended by crews at both ends that live & collect health data for up to a year or more​. And of course, ethical experiments on the GRx for mammalian reproduction would be carried out, first on rodents and then progressing to higher primates if successful.

Left: Conceptual illustration depicting a LEO Moon-Mars dumbbell partial gravity facility constructed from Starship payload-sized habitats tethered by airbeams and serviced by Dragon capsules. Rectangular solar arrays deploy by hanging at either end as spin is initiated via thrusters at Mars module. Center: Image of an inflated airbeam demonstration. Right: diagram of an airbeam stowed for transport and after deployment. Credit: Joe Carroll

What if these experiments determine that having children in lower gravity is not possible and our only path forward are free-space rotating settlements? Physics and human physiology require that they be large enough for settlers to tolerate a 1g spin rate to prevent disorientation. As originally envisioned by O’Neill, the diameter of his Island One space settlement would be about 500 meters.

Conceptual illustration of an Island One space settlement. The living space sphere is sized at about 500m in diameter. Credits: Rick Guidice / NASA

As originally proposed, these settlements would be located outside the Earth’s magnetic field at the L5 Earth-Moon Lagrange Point necessitating that they be shielded with enormous amounts of lunar regolith to protect occupants from radiation. Their construction requires significant technology development and infrastructure (e.g. mass drivers on the Moon, automated assembly in space, advances in robotics, power sources, etc…)​. Much of this will eventually be done anyway as space development progresses…however, knowing the GRx (if it is equal to 1g) may foster a sense of urgency​.

Some may take the alternative viewpoint that if we know that Earth’s gravity works just fine we could proceed directly to free-space settlements if we could overcome the mass problem. This is the approach Al Globus and Tom Marotta took in their book The High Frontier: An Easier Way with Kalpana One​, a 450m diameter cylindrical rotating free-space settlement located in equatorial low Earth orbit (ELEO) protected by our planet’s magnetic field, thereby reducing the mass significantly because there would be far less need for heavy radiation shielding.

Artist impression of Kalpana One rotating free-space settlement located in equatorial low Earth orbit. Credits: Bryan Versteeg / Spacehabs.com

But there may be an even easier way. Kasper Kubica has proposed a 10 year roadmap to the $10M condo in ELEO based on Kalpana Two, a scaled down version of the orbital settlement described by Al Globus in a 2017 Space Review article.

Artist rendering of the inside of a rotating free-space settlement based on the Kalpana Two design, with a length of 110m and diameter of 125m. Credits: Bryan Versteeg / Spacehabs.com

Even though these communities would be lower mass, they will still require significant increases in launch rates to place the needed materials in LEO, especially near the equator​. Offshore spaceports, like those under development by The Spaceport Company, could play a significant role​ in this infrastructure. Legislation providing financial incentives to municipalities to build spaceports would be helpful, such as The Secure U.S. Leadership in Space Act of 2024 introduced in Congress last month. The new law (not yet taken up in the Senate) would amend the IRS Code to allow spaceports to issue tax-exempt Muni bonds for infrastructure improvements.

Wouldn’t orbital debris present a hazard for settlements in ELEO?​ Definitely yes, and the National Space Society is shaping policy in this area. The best approach is to emphasize “light touch” regulatory reform on salvage rights, with protection and indemnity of the space industry to encourage recycling and debris removal.​ Joe Carroll has suggested a market-based approach that would impose parking fees for high value orbits, which would fund a bounty system for debris removal. This system would incentivize companies like CisLunar Industries, Neumann Space and Benchmark Space Systems, firms that are developing space-based processes to recycle orbital debris into useful commodities such as fuel and structural components.

Further down the road in technology development and deeper into space, advances in artificial intelligence and robotics will enable autonomous conversion of asteroids into rotating space settlements, as described by David Jensen in a paper uploaded to arXiv last year.​ This approach significantly reduces launch costs by leveraging in situ resource utilization. Initially, small numbers of “seed” tool maker robots are launched to a target asteroid​ along with supplemental “vitamins” of components like microprocessors that cannot be easily fabricated until technology progresses, to complete the machines. These robotic replicators use asteroid materials to make copies of themselves and other structural materials eventually building out a rotating space settlement. As the technology improves, the machines eventually become fully self-replicating, no longer requiring supplemental shipments from Earth.

Artist impression of a rotating space settlement constructed from asteroid materials. Credits: Bryan Versteeg, spacehabs.com

Leveraging AI to enable robots to build space settlements removes humans from the loop initially, eliminating risk to their health from exposure to radiation and microgravity​. Send it the robot home builders – families then safely move in later. There are virtually unlimited supplies in the asteroid belt to provide feedstock to construct thousands of such communities.

Artist impression of the interior of Stanford Torus free-space settlement. Advances in artificial intelligence and robotics will enable autonomous self replicating machines that could build thousands of such communities from asteroid material. Credits: Don Davis / NASA

If rotating space settlements with Earth-normal gravity become the preferred choice for off-Earth communities, where would be the best location, the prime real estate of the solar system? Jim Logan has identified the perfect place with his Essential Seven Settlement Criteria.

  • Low Delta-V​ – enabling easy access with a minimum of energy
  • Lots of RESOURCES​ … obviously!
  • Little or No GRAVITY WELL​ – half way to anywhere in the solar system
  • At or Near Earth Normal GRAVITY for​
    People, Plants and Animals ​- like what evolved on Earth
  • Natural Passive 24/7 RADIATION Protection​ – for healthy living
  • Permit Large Redundant Ecosystem(s)​ – for sustenance and life support
  • Staging Area for Exploration and Expansion​
    (including frequent, recurrent launch windows)​

Using this criteria, Logan identified Deimos, the outermost moon of Mars, as the ideal location. As discussed above, AI and robotic mining technology improvements will enable autonomous boring machines to drill a 15km long core through this body with a diameter around 500 meters – sized for an Island One space settlement to fit perfectly.

Conceptual illustration of a 500 meter wide by 15km long core bored through Deimos. Credit: Jim Logan

In fact, 11 Island One space colonies (minus the mirrors) strung end to end through this tunnel would provide sea level radiation protection and Earth normal artificial gravity for thousands of healthy settlers.

Left: Artist impression of an Island One space settlement. Credits: Rick Guidice / NASA. Right: To scale depiction of 11 Island One space settlements strung end-to-end in a cored out tunnel through Deimos providing sea level radiation protection and Earth normal artificial gravity. Credit: Jim Logan

In conclusion, the GRx for reproduction will inform where biologically self-sustaining healthy communities can be established in space. If we find that the GRx is equal to Earth’s normal level, free-space settlements with artificial gravity will be the safest and healthiness solution for humans to live and thrive throughout the solar system. The sooner we determined the GRx the better, for current plans for settling the Moon or Mars may need to be altered to consider rotating space colonies, which will require significant infrastructure development and regulatory reform​. Alternatively, since we know Earth’s gravity works just fine, we may choose to skip determination of the GRx and start small with Kalpana in low Earth orbit. Eventually, artificial intelligence will enable safe, autonomous self-assembly of space settlements from asteroids. The interior of Deimos would be the perfect place to build safe, healthy, biologically self-sustaining space settlements for thousands of families to raise their children, establishing a beachhead from which to explore the rest of the solar system and preserve the light of human consciousness.

Update June 3, 2024: Here is a recording of my presentation on this topic at ISDC 2024.

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Minerva Space Settlement and University of Space Exploration

Conceptual illustration of the Minerva Space Settlement in orbit around Jupiter’s moon Ganymede. Credits: Minerva Project Team

Space Settlement Progress typically features the latest advancements in technology that are enabling the settlement of space.  This post will be a little different.  When attending the International Space Development Conference last May I was impressed by a team of students from Highschool Colegiul National Andrei Saguna in Romania, who had conceived of a space settlement in orbit around Jupiter’s satellite Ganymede which they call Minerva.  The project was an entry in the National Space Societies’ Space Settlement Contest, and for which they won a second place award for 9th graders.  While admiring their poster I was approached by Maria Vasilescu, who proudly described their project and agreed to collaborate with me on this post. She spoke perfect English, shared marketing materials (key chains, buttons and bookmarks with QR codes linking to their website) and explained that the primary purpose of Minerva would be a deep space location for a University of Space Exploration.  I was intrigued by the concept and was struck by Maria and her teammates’ enthusiastic vision of humanity’s future in space.  I wanted to know more about what motivated this group of teenagers to come together and create such an imaginative project, as youths like them will be future pioneers on the High Frontier.  Maria agreed to coordinate with her team on an interview via email about Minerva.

The Minerva Project Team and their poster session at ISDC 2023, a second prize winner for 9th graders of the NSS Space Settlement Contest. Credits: Minerva Project Team: clockwise from lower right: Bodean Mircea-Sorin, Ana Radus, Andrei Ioan Prunea, Alexandra Nica, Alexandra Maria Nemes, Maria Vasilescu

SSP: How did the team come up with this Minerva concept?

Minerva: We took inspiration from our school which gave us a lot of opportunities to which we owe a lot and we wanted to build such a university in the final frontier.

SSP: You mentioned stumbling across some obstacles during your journey but sticking together by motivating each other.  Is this an experience you feel comfortable sharing?

Minerva: One of the hardest things was to think about all the aspects that go into making a space settlement as ninth graders, such as the form [Forum on the website], which was decided in the last week, or the economical part. But we managed to meet often and brainstorm to come up with better ideas.

SSP: You said that the project helped you discover your true selves. Can you explain how this came about?

Minerva: We developed ourselves and our passions and we found out what we like because it covers a broad area of subjects beyond science. We managed to see by which area we are drawn to and enjoy actually researching.

SSP: You’ve stated that one of the reasons for building Minerva is to invent new lifestyles different from those that exist on Earth. How do you envision lifestyles changing in space?

Minerva: The university can prepare you for life in space, which will be an important part in the humans’ future, therefore we don’t want to invent new lifestyles, but incorporate space in the ones that already exist.

SSP: You’ve proposed auctioning a Minerva NFT to fund your efforts and future experiments.  Would this be the sole source of financing for the project, and will it be sufficient?  What about simply charging tuition for the USE?

Minerva: Everything on our settlement is given and made by us for the people so they don’t need to have money to buy material things. And because we have worked to make almost everything renewable and green, the funds MinervaNFT will bring are more than sufficient for everything else. And as for tuition, we feel like putting students through an exam such as the one that defines their attendance to USE is stressful enough as it is. However, the students will need to pay for the transport from Earth to the settlement.

SSP: There does not appear to be any trade or economic activity on Minerva, only academic studies. Students may choose to return to Earth or stay on the space station after they complete their studies. If they stay, have you considered the possibility of graduates developing and marketing other industries such as software development, robotics, mining water from Ganymede as rocket fuel, intellectual property on life support systems, or many other potential industries that could arise from scientific innovation that would take place on a space settlement? Or would this be totally an academic institution?

Minerva: It is not a totally academic institution because we have two thirds of the ship which will be occupied by students that remained on the settlement. But here, you don’t need money, everything being provided by us, so people don’t work for money, they work to occupy time, for enjoyment. If they do develop other industries, it will be fully for the greater good of humanity and the future of our kind, not for money.

SSP: The location chosen for Minerva is very challenging from an engineering perspective.  Although Ganymede is not deep in Jupiter’s magnetosphere, and has its own magnetic field which could help mitigate exposure, the location will still have high levels of radiation if unprotected, which complicates the design because much more mass is needed to provide adequate shielding to be safe for humans.  In addition, travel times to Jupiter are quite long even with improved propulsion which you’ve indicated would be as high as four years for students wanting to make the journey.  Finally, solar energy at Jupiter’s remote distance from the sun requires that photovoltaic arrays be enormous to provide sufficient energy. A good compromise might be the asteroid Ceres, which is believed to be 25% water and does not have a magnetic field generating high radiation like what would be experienced at Jupiter.  Others have proposed this asteroid as a good destination for space settlement.  Why not locate the settlement in a more accessible and hospitable environment that might reduce costs? 

Minerva: The main reason we chose such a far away location is precisely because we want to explore as much as possible of the cosmos. It’s not that we don’t want a closer location, it’s just that we know very little about Jupiter and its surrounding moons and further and this university can offer humanity an opportunity to explore it and send the research back to Earth. At the same time, we have taken the radiation into consideration and just how today’s spaceships have protection against it, so how [sic] our settlement, but ten times more efficient.

SSP: The sources of power for Minerva include solar arrays and nuclear fission, but you excluded fusion energy because it is currently experimental.  By the time it will be technologically possible to travel to Jupiter and establish infrastructure that far out in the solar system, we will have developed fusion energy for use on Earth as well as in space.  The preliminary design work for a Direct Fusion Drive for rapid transit to the outer planets has been started by Princeton Satellite Systems and the Fusion Industry Association just came out with their third annual report stating that the industry has now attracted over $6 billion in investment.  When it is feasible to begin work on Minerva, fusion power sources will likely be available. Will you be updating your project plan as new technologies become available? 

Minerva: Of course, we are sure that many aspects of our settlement can be improved by future developments in science, engineering and many other fields. As much as possible, we will incorporate them into our settlement. As mentioned in our paper, when talking about technological advances that may happen, we have to keep up with innovation and incorporate them to help us fulfill every need when travelling to space.

SSP: You raised the concern that Earth is approaching a major crisis with population growth putting a strain on Earth’s vital resources.  You also said that the purpose of the space community is to sustain humanity if Earth’s environment became unfavorable for life.  In selecting the location of Minerva, when considering Mars and its orbital distance, you said that even though it fulfills most of your requirements “…the disadvantage of Mars its it proximity to Earth…” and it “…is too close to our planet in order for us to choose it as the proper placement for the spacecraft.”  Why must Minerva be distant from Earth if the planet is in crisis in the future and why isn’t the orbit of Mars, at 56 million kilometers, considered not far enough away?

Minerva: Mars wasn’t a viable option because, as we have stated before, the purpose of the USE is to gather information and scientific news that can only be found in the farther cosmos. We already know a lot about Mars and planets in close proximity to Earth, we want to venture further, discover and experiment with more than we already have.

SSP: Some surveys say that young people live in fear of the future due to climate change.  Many media outlets amplify this doom and gloom.  However, some economists point out that using the United Nation’s own data from the Intergovernmental Panel on Climate Change, with the predicted increase in temperature by the year 2100, global GDP will be reduced by only 4% to deal with climate related impacts.  Although it is clear that we should eventually reduce our dependance on fossil fuels this is not an existential threat.   Plus, technological innovation continues to improve efficiency in resource utilization, energy development and agriculture, enabling higher standards of living notwithstanding increasing population growth. 

The viewpoint that the Earth is in “crisis” is closely aligned with Elon Musk’s motivation, who believes it is urgent that we become a multiplanetary species, to have a “Plan B” in case of a planetwide catastrophe.  Jeff Bezos has a different perspective, that heavy industrial activity could be moved off world to preserve the Earth’s natural environment and to improve humanities’ standard of living though utilization of unlimited space resources.  

Gerard K. O’Neill saw the promise of space settlement as a way to solve Earth’s problems through the humanization of space.  He saw it as a way to end poverty for all humans, provide high-quality living space that would continue to grow robustly, to moderate population growth without war, famine, dictatorship or coercion; and to increase individual freedom.  Does your team share the same anxiety about the future as other young people: that life on Earth is doomed and therefore, we need to build Minvera as a sanctuary to preserve humanity?  Or do you see it as one among many options for space settlement to improve life on Earth and beyond, as outlined in O’Neill’s vision?

Minerva: We see Minerva as a place where people that are smart and passionate about space have a chance to make scientific discoveries that would be impossible to do on Earth. Aligned with Gerald O’Neil’s [sic] view, we believe that humans should expand into space whether it is as a Plan B or by harvesting resources from other planets or celestial objects. With the help of Minerva, the smartest children of their generation will be able to experience these scenarios and be closer to the future. We don’t see Minerva as a Plan B for humanity, students that have finished their 4 years being able to return to earth, but rather as a place where people can enjoy a stress free and enjoyable environment. Therefore Minerva is preparing smart youngsters to be able to take advantage of any of the two cases. If they choose to remain on Earth, the knowledge that they acquired while in the USE will definitely increase humanity’s survivability against the existential threats mentioned.

SSP: You’ve created a survey [what was earlier referred to as a “Form” and can be found at the “Forum” link on the Minerva website] for anyone to express their opinion about your project and the prospect of living in space.  Will you use this feedback to improve your project? 

Minerva: Maybe in the future, yes. We have encouraged people to complete the survey honestly and there’s always place for improvement for anything. And the second reason is to observe humanity’s view on such a settlement. In creating such a complex space settlement, you need to align your view with the society’s beliefs, them being the ones who will eventually populate it.

SSP: Does your team expect to remain engaged with the project as you progress in your education and after you eventually establish your careers here on Earth?

Minerva: It was certainly an experience we will treasure for a long time, but not everything has to be drawn out. I think this project took a lot of work and effort and we want to invest into something new, see this contest from as many angles as possible while we can. This project like no other can incorporate so many aspects of society from which you can discover your biggest passions. Talking to everyone in our group, we found that each one of us enjoyed a different part of the project and we believe that that was the key to our win. We were all doing something we are passionate about and therefore worked even harder for the final result. Now that we’ve learned what topics intrigue us, we can start doing even more work in that domain. We believe that this project is the perfect opportunity and will open numerous doors in any future career path. We strongly recommend this contest to anyone wondering whether they should put their effort into it or not.

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Highlights from the International Space Development Conference

Conceptual illustration of Mag Mell, a rotating space settlement in the asteroid belt in orbit around Ceres – grand prize winner of the NSS Student Space Settlement Design Contest. Credits: St. Flannan’s College Space Settlement design team*

In this post I summarize a few selected presentations that stood out for me at the National Space Society’s International Space Development Conference 2022 held in Arlington, Virginia May 27-29.

First up is Mag Mel, the grand prize winner of the NSS Student Space Settlement design contest, awarded to a team* of students from St. Flannan’s College in Ireland. This concept caught my eye because it was in part inspired by Pekka Janhunen’s Ceres Megasatellite Space Settlement and leverages Bruce Damer’s SHEPHERD asteroid capture and retrieval system for harvesting building materials.

The title Mag Mell comes from Irish mythology translating to “A delightful or pleasant plain.” These young, bright space enthusiasts designed their space settlement as a pleasant place to live for up to 10,000 people. Each took turns presenting a different aspect of their design to ISDC attendees during the dinner talks on Saturday. I was struck by their optimism for the future and hopeful that they will be representing the next generation of space settlers.

Robotically 3D printed in-situ, Mag Mell would be placed in Ceres equatorial orbit and built using materials mined from that world and other bodies in the Asteroid Belt. The settlement was designed as a rotating half-cut torus with different angular rotation rates for the central hub and outer rim, featuring artificial 1G gravity and an Earth-like atmosphere. Access to the surface of the asteroid would be provided by a space elevator over 1000 km in length.

* St. Flannan’s College Space Settlement design team: Cian Pyne, Jack O’Connor, Adam Downes, Garbhán Monahan, and Naem Haq

Conceptual illustration of a habitat on Mars constructed from self-replicating greenhouses. Credits: GrowMars / Daniel Tompkins

Daniel Tompkins, an agricultural scientist and founder of GrowMars, presented his Expanding Loop concept of self replicating greenhouses which would be 3D printed in situ on the Moon or Mars (or in LEO). The process works by utilizing sunlight and local resources like water and waste CO2 from human respiration to grow algae for food with byproducts of bio-polymers as binders for 3D printing blocks from composite concretes. Tompkins has a plan for a LEO demonstration next year and envisions a facility eventually attached to the International Space Station. He calculates that a 4000kg greenhouse could be fabricated from 1 year of waste CO2 generated by four astronauts. An added bonus is that as the greenhouse expands, an excess of bioplastic output would be produced, enabling additional in-space manufacturing.

Diagram depicting GrowMars Expanding Loop algae growing process to create greenhouse blocks and byproducts such as proteins and fertilizer. Credits: GrowMars / Daniel Tompkins.
Illustration of a portion of the Spacescraper tethered ring from the Atlantis Project. Credits: Phil Swan

Phil Swan introduced the Atlantis Project, an effort to create a permanent tethered ring habitat at the limit of the Earth’s atmosphere, which he calls a Spacescraper.  The structure would be placed on a stayed bearing consisting of two concentric rings magnetically attached and levitated up to 80 km in the air.  In a white paper available on the project’s website, details of the force vectors for levitation of the device, the value proposition and the economic feasibility are described. As discussed during the talk at ISDC, potential applications include:

  • Electromagnetic launch to space
  • Carbon neutral international travel
  • Evacuated tube transit system
  • Astronomical observatories
  • Communication and internet
  • Solar energy collection for electrical power
  • Space tourism
  • High rise real estate

Phil Swan will be coming on The Space Show June 21 to provide more details.

Conceptual illustration of a Mars city design with dual centrifuges for artificial gravity. Credits: Kent Nebergall

Finally, the Chair of the Mars Society Steering committee and founder of MacroInvent Kent Nebergall, gave a presentation on Creating a Space Settlement Cambrian Explosion. That period, 540 million years ago when fossil evidence goes from just multicellular organisms to most of the phyla that exist today in only 10 million years, could be a metaphor for space settlement in our times going from extremely slow progress to a quick expansion via every possible solution. Nebergall suggests that we may be on the verge of a similar growth spurt in space settlement and proposes a roadmap to make it happen this century.

He envisions three settlement eras beginning with development of SpaceX Starship transportation infrastructure transitioning to robust cities on Mars with eventual para-terraforming of that planet. He also has plans for how to overcome some of the most challenging barriers – momentum and money. Stay tuned for more as Kent has agreed to an exclusive interview on this topic in a subsequent post on SSP as well as an appearance on The Space Show July 10th.